
  <template>
    <div class="article-container">
      <van-nav-bar class="page-nav-bar" left-arrow @click-left="$router.back()" title="黑马头条"></van-nav-bar>

      <div class="main-wrap">
        <div v-if="loading" class="loading-wrap">
          <van-loading color="#3296fa" vertical>加载中</van-loading>
        </div>

        <div class="article-detail"  v-else-if="article.title">
          <!-- 文章的标题 -->
          <h1 class="article-title">{{ article.title }}</h1>

          <!-- 用户的信息 -->
          <van-cell class="user-info" center :border="false">
            <van-image
              class="avatar"
              slot="icon"
              round
              fit="cover"
              :src="article.aut_photo"
            />
            <div slot="title" class="user-name">{{ article.aut_name }}</div>
            <div slot="label" class="publish-date">{{ article.pubdate | relativeTime }}</div>
            <follow-user
              class="follow-btn"
              v-model="article.is_followed"
              :user-id="article.aut_id"
            />
          </van-cell>

          <!-- 文章的内容 -->
          <div ref="article-content" class="article-content  markdown-body" v-html="article.content"></div>
          <van-divider>正文结束</van-divider>
          <comment-list
            :source="article.art_id"
            :list="commentList"
            @onload-success="totalCommentCount = $event.total_count"
            @reply-click="onReplyClick"
          />

          <div class="article-bottom">
            <van-button
              class="comment-btn"
              type="default"
              round
              size="small"
              @click="isPostShow = true"
            >写评论</van-button>
            <van-icon
              class="comment-icon"
              name="comment-o"
              :badge="totalCommentCount"
            />
            <collect-article
              class="btn-item"
              v-model="article.is_collected"
              :article-id="article.art_id"
            />
            <like-article
              class="btn-item"
              v-model="article.attitude"
              :article-id="article.art_id"
            />
            <van-icon name="share" color="#777777"></van-icon>
          </div>
          <!-- 评论发布 -->
          <van-popup
            v-model="isPostShow"
            position="bottom"
          >
            <comment-post
              :target="article.art_id"
              @post-success="onPostSuccess"
            />
          </van-popup>
          <!-- 评论发布 -->
        </div>

        <!-- 404 -->
        <div class="error-wrap" v-else-if="errStatus === 404">
          <van-icon name="failure" />
          <p class="text">该资源不存在或已删除！</p>
        </div>

        <!-- 因网络以及服务器原因加载失败 -->
        <div v-else class="error-wrap">
          <van-icon name="failure" />
          <p class="text">内容加载失败！</p>
          <van-button class="retry-btn">点击重试</van-button>
        </div>
      </div>
      <van-popup
        v-model="isReplyShow"
        position="bottom"
        style="height: 100%;"
      >

        <comment-reply
          v-if="isReplyShow"
          :comment="currentComment"
          @close="isReplyShow = false"
        />
      </van-popup>

    </div>
  </template>

<script>
import { getArticleById } from '@/api/article.js'
import { ImagePreview } from 'vant'
import FollowUser from '@/components/users-follow/index.vue'
import CollectArticle from '@/components/collect-article/index.vue'
import LikeArticle from '@/components/like-article'
import CommentList from './components/comment-list.vue'
import CommentPost from './components/comment-post'
import CommentReply from './components/comment-reply'
export default {
  name: 'ArticleIndex',
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true
    }
  },
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  created () {
    this.loadArticle()
  },
  provide: function () {
    return {
      articleId: this.articleId
    }
  },
  data () {
    return {
      article: {}, // 文章详情
      loading: true, // loading 状态
      errStatus: 0, // 失败的状态码
      followLoading: false,
      totalCommentCount: 0,
      isPostShow: false, // 控制发布评论的显示
      commentList: [], // 评论列表
      isReplyShow: false,
      currentComment: {} // 当前点回的评论项
    }
  },
  methods: {
    // 加载文章详情
    async loadArticle () {
      this.loading = true
      try {
        const { data } = await getArticleById(this.articleId)
        this.article = data.data
        setTimeout(() => {
          this.previewImage()
        })
      } catch (error) {
        if (error.response && error.response.status === 404) {
          this.errStatus = 404
        }
      }

      this.loading = false
    },
    previewImage () {
      // 获取所有img图片节点
      const articleContent = this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      const images = []

      imgs.forEach((item, index) => {
        images.push(item.src)

        item.onclick = () => {
          ImagePreview({
            images: images,
            startPosition: index
          })
        }
      })
    },
    onPostSuccess (data) {
      // 弹出层关闭
      this.isPostShow = false
      // 发布内容渲染到列表顶部
      this.commentList.unshift(data.new_obj)
    },

    onReplyClick (comment) {
      this.currentComment = comment

      // 评论回复弹出层显示
      this.isReplyShow = true
    }
  }
}
</script>

<style scoped lang="less">
@import "./github-markdown.css";
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
    .btn-item {
      border: none;
      padding: 0;
      height: 40px;
      line-height: 40px;
      color: #777777
    }
  }
}
</style>
